US4396471A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gold plating bath and method using maleic anhydride polymer chelate
Assignee: TECHNIC Inc A RHODE ISLAND CORP
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Filing: 1981-12-14
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Granted: 1983-08-02
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Expires: 2001-12-14
Abstract
Abstract An all-purpose gold cyanide electroplating bath utilizes a cobalt, nickel, or indium hardener as a chelate with the acid form of a methyl vinyl ether/maleic anhydride interpolymer. The bath is capable of producing high levels of hardness in deposits that are substantially pure gold; it is efficient, very stable, resistent to contamination, and it is well-suited for utility at a wide range of current densities.
Inventors
- 👤 Augustus Fletcher
- 👤 William L. Moriarty
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:38
CPC Classifications
C; C25; C25D; C25D3/00; C25D3/02; C25D3/48; C25D3/56; C25D3/62
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
99 words
A gold plating bath comprising, on a per liter basis, an aqueous solution of: an alkali metal gold cyanide in an amount providing about 1 to 41 grams of gold, calculated as the metal; free alkali metal cyanide in an amount effective to prevent precipitation of the metal values; an effective amount of an electrolyte ingredient; and about 0.05-10.0 grams of cobalt, nickel, indium, or a mixture thereof, in the form of a chelate with a hydrolyzed interpolymer of a methyl or ethyl vinyl ether and maleic anhydride, said bath having a pH value of about 3.0 to 13.0.
Claim 2
Dependent Claim
99 words
A gold plating bath comprising, on a per liter basis, an aqueous solution of: an alkali metal gold cyanide in an amount providing about 1 to 41 grams of gold, calculated as the metal; free alkali metal cyanide in an amount effective to prevent precipitation of the metal values; an effective amount of an electrolyte ingredient; and about 0.05-10.0 grams of cobalt, nickel, indium, or a mixture thereof, in the form of a chelate with a hydrolyzed interpolymer of a methyl or ethyl vinyl ether and maleic anhydride, said bath having a pH value of about 3.0 to 13.0.
Claim 3
Dependent Claim
24 words
The bath of claim 1 wherein said electrolyte comprises a weak organic acid, and zero to an effective amount of a salt such acid.
Claim 4
Dependent Claim
11 words
The bath of claim 2 wherein said organic acid is citric.
Claim 5
Dependent Claim
35 words
The bath of claim 2 wherein said electrolyte comprises a mixture of said weak organic acid with an inorganic acid selected from the group consisting of acids that furnish the phosphate, nitrate and sulfate radicals.
Claim 6
Dependent Claim
19 words
The bath of claim 1 additionally including an alkali metal hydroxide for adjustment of said pH to said value.
Claim 7
Dependent Claim
19 words
The bath of claim 5 wherein said gold and alkali metal cyanides, and said hydroxide, are compounds of potassium.
Claim 8
Dependent Claim
28 words
The bath of claim 1 wherein said pH value is less than about 7.0, and wherein said bath has a specific gravity of about 4° to 30° Baume.
Claim 9
Dependent Claim
14 words
The bath of claim 7 wherein said pH value is about 4.0 to 6.0.
Claim 10
Dependent Claim
92 words
In a method of electroplating hard gold deposits upon a workpiece, the steps comprising: immersing a workpiece having an electrically conductive surface in the gold plating bath of claim 1, 3, 6, or 7; maintaining the temperature of said bath at about 20° to 75° Centrigrade; applying an electrical potential across said workpiece and an anode to provide a current density of about 0.1 to 165 amperes per square decimeter at said workpiece, and to thereby effect electrodeposition of gold in the desired thickness; and removing the electroplated workpiece from said bath.
Claim 11
Dependent Claim
47 words
The method of claim 9 wherein said temperature is about 35° to 50° Centigrade wherein said pH value is about 4.0 to 6.0, and wherein said current density has a maximum value of 75 amperes per square decimeter, said bath and/or said workpiece being agitated during electroplating.
Claim 12
Dependent Claim
36 words
The method of claim 10 wherein the temperature of said bath is above about 40° Centigrade and said current density is at least 5.0 amperes per square decimeter, said method constituting a high speed electroplating process.
References Cited (Backward Citations)
US2047398A
Cited
US2812299A
Cited
US2752281A
Cited
US3087853A
Cited
US2905601A
Cited
US3149057A
Cited
US3149058A
Cited
US3271310A
Cited
US3432445A
Cited
US3407126A
Cited
US3424597A
Cited
US3672969A
Cited
US3856638A
Cited
US3716463A
Cited
US3706634A
Cited
US3787463A
Cited
US3770596A
Cited
US3864222A
Cited
US3902977A
Cited
US4186064A
Cited
US4197172A
Cited
US4253920A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-08-01 | 1987-01-31 | 1987-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-01 | 1991-01-31 | 1991-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-01 | 1995-01-31 | 1995-08-02 | $7700.00 | Window Closed / Lapsed |